1. Field of the Invention
The present invention relates to novel thermoplastic polymer blends, and, more especially, to certain polyamide/polyetheramide/thermoplastic elastomer alloys which are easily molded or extruded into useful shaped articles having enhanced impact strength.
2. Description of the Prior Art
Shaped articles comprised of polyamides, whether molded or extruded, are widely used for numerous applications requiring excellent mechanical properties, notably a very high impact strength.
As the requirements in this respect have been steadily increasing, various means have been proposed to this art to improve impact strength. Particularly representative of such means is the addition to polyamides of certain polymers which are clearly elastomeric in nature.
Exemplary of such impact modified polymers, the following are representative:
(a) Copolymers, whether or not graft polymers and whether or not crosslinked, based essentially on butadiene, styrene and acrylonitrile (U.S. Pat. Nos. 3,134,746, 3,218,371, 3,267,175, 4,381,371);
(b) Copolymers based on monoolefins, more particularly on ethylene and acrylic acid, methacrylic acid, vinyl acetate, and the like (DE-AS 19,08,468, 27,13,537, British Patent No. 998,439, U.S. Pat. No. 4,362,846, published Japanese application No. 15.5318);
(c) Copolymers of ethylene, propylene and diene, designated EPDM, the diene in most cases being 1,3-butadiene or isoprene NL 83.02602, Stamicarbon; KUNSTSTOFFE, 75, 3, p. 160 (1985)!;
(d) Copolymers, whether or not graft polymers and whether or not crosslinked, based essentially on methyl methacrylate, butadiene and styrene (U.S. Pat. Nos. 3,668,274, 3,796,771, 3,984,497, published Japanese application No. 76.87138);
(e) Mixtures of polyolefins, copolymers of butadiene and acrylonitrile (DE-OS 27,34,693);
(f) Chlorinated polyethylene elastomers (U.S. Pat. No. 4,207,404);
(g) Nitrile rubbers, such term designating essentially copolymers of 1,3-butadiene or isoprene with acrylonitrile (EP 131,113 A).